Resiliently mounted rail for rail vehicles

ABSTRACT

A rail assembly in which the shanks of a rail between the head and the base have one pair of outwardly facing downwardly tapering flank surfaces and a frame flanking the rail has a pair of downwardly tapering inwardly facing flank surfaces spaced from and juxtaposed with the surfaces of the rail. The surfaces receive between them under precompression so as to generate a spring constant of 2 KN/mm to 8 KN/mm per meter of rail length, elastic intermediate layers which resiliently support the rail. One of the pairs of surfaces is composed of angularly adjoining upper and lower portions while the other is rectilinear over the height thereof juxtaposed with the first mentioned pair.

FIELD OF THE INVENTION Cross-Reference to Related Application

This application is a National Phase of Patent EP 89,/00,607 filed May30, 1989 and based, in turn, upon German National application G 88 07195.2 filed Jun. 1, 1988 under the International Convention.

The invention relates to a resiliently mounted rail for rail vehicles,wherein the laterally limiting surfaces located below the rail head abutagainst the inner lateral surfaces of a frame, flanking the rail wherebyin the area of abutment the lateral limiting surfaces of the rail and/orthe inner lateral surfaces of the frame are subdivided into twosegments--a lower and an upper segment--each of them taperingdownwardly.

BACKGROUND OF THE INVENTION

In known rails of the aforementioned kind, the shape of thecharacteristic curve resulting from the presence of the elasticintermediate layer when the rail is under load is solely determined bythe characteristics of the material of the elastic intermediate layer.This is particularly disadvantageous in a rail with standard railprofile (U.S. Pat. No. 3,525,472), because here the angle formed by thelateral limiting surfaces of the rail below the rail head with thevertical is very large in the upper segment and very small in the lowersegment, so that when the characteristic curve for the vertical load ofthe rail is correctly established, the elastic intermediate layers aretoo hard for the horizontally occurring load, while when thecharacteristic curve for the horizontal load of the rail is correctlyestablished, the elastic intermediate layers are too soft for thevertical load. Therefore, in practice there is always a compromisesolution, which does not offer an optimal shape of the characteristiccurve in any load direction. In a rail of this type, the soundattenuation is extraordinarily low.

An improved sound damping is achieved with another known rail, whereinin the area of the rail web a rectilinearly downward tapering area isprovided, over which the rail abuts against a frame via elasticintermediate layers, the inner lateral surfaces of the frame runningalso rectilinearly (DE-OS 35 40 128). In this rail, the lateral surfaceslimiting the rail below the rail head, as well as the inner lateralsurfaces limiting the frame form respectively only one angle with thevertical. This allows for a more correct setting of the characteristiccurve.

OBJECT OF THE INVENTION

It is the object of the invention to improve a rail of theaforementioned kind, so that it is possible to establish an optimalcharacteristic curve for each application and in a way which is superiorto the aforementioned known rail.

SUMMARY OF THE INVENTION

According to this invention, in the upper segment the lateral limitingsurfaces of the rail form with the vertical an angle ranging between 0°and 10°, in the lower segment the lateral limiting surfaces of the railform with the vertical an angle ranging between 15° and 30° and theinner lateral limiting surfaces of the frame form with the vertical anangle ranging between 5° and 30°.

According to a feature of the invention, the inner lateral limitingsurfaces of the frame form an angle with the vertical, which rangesbetween 15° and 40°, in the lower segment, the inner lateral surfaces ofthe frame form an angle with the vertical ranging between 0° and 10°,and the lateral limiting surfaces of the rail form with the vertical anangle between 0° and 30°.

This selection of angles in the upper and lower segments of the laterallimiting surfaces makes it possible to establish to a large extent anoptimal characteristic curve.

The angles can be so selected that the angle formed in the upper segmentby the surfaces defining the rail and the vertical equals approximately3°, the angle formed in the lower segment by the surfaces defining therail with the vertical equals approximately 20°, and the angle formed bythe inner lateral limiting surfaces of the frame with the verticalequals approximately 15° angle formed in the upper segment by the innerlateral surfaces of the frame and the vertical can equal approximately20°, the angle formed in the lower segment by the inner lateral surfacesof the frame and the vertical can equal approximately 3°, and the angleformed by the lateral surfaces limiting the rail with the verticalequals approximately 18°.

In a particularly simple embodiment of the invention, which allows forthe use of a standard rail, the elastic intermediate layer extends up tothe web of a standard rail.

Each elastic intermediate layer between the rail and the frame can beprestressed in such a manner that it imparts a spring constant between 2KN/mm and 8 KN/mm, preferably 3.5 KN/mm for each 1 m of rail.

Each elastic intermediate layer can be provided with compartments. Bycorrespondingly selecting the shape and the arrangement of thesecompartments, the spring excursion over the possible elastic stroke ofthe rail can be of any desired configuration and, in this way, adjustedto all requirements.

In order to insure that no dirt penetrates these compartments therebyimpairing their functioning capability, the compartments are arrangedinside the elastic intermediate layer.

The sizes of the compartments is selected so that under normal load, theelastic stroke of the rail ranges between 1 mm and 15 mm, preferably 6mm. This stroke is sufficient to achieve the desired sound damping andat the same time requires only very little space.

A particularly simple way of influencing the characteristic curve sothat it changes its direction when the normal load is reached, theclearances have basically the shape of a rectangle, which extends in thedirection of the lateral surfaces limiting the rail, so that the widthof the rectangle is so selected that it reaches zero under normal railload.

According to a further feature of the invention, in each elasticintermediate layer there are at least two such compartments.

In a further development of the invention, the elastic intermediatelayers are mutually connected by a connecting piece surrounding the railbase with characteristics similar to those of the elastic intermediatelayers, whereby a free space is provided between the rail base and theconnection piece or between the connection piece and the frame bottom,the height of this free space corresponding to the elastic stroke of therail reached under normal load. In this way, the correct arrangement ofthe elastic intermediate layers is insured during the rail mounting, aswell as after that. For the sake of simplicity, the connection piece canbe made of the same material as the elastic intermediate layers.

In order to round out the break occurring in the characteristic curvewhen the normal load of the rail is surpassed, the connection piece canbe provided with projections which extend over the entire height of thefree space underneath the rail base.

In this way, a certain lateral movability becomes possible for the railbase, since the connection piece is provided with recesses on its sidefacing away from the rail base.

The penetration of water between the rail and the frame can be preventedwhen the elastic intermediate layer is provided in the upper area onboth sides with approximately triangular projections.

In a preferred embodiment of the invention, at the web of a standardrail, on each side a molded part is attached, whose surface facing awayfrom the rail web performs the functions of a lateral surface limitingthe rail.

In order to insure that the position of the molded part is unchangeablyset, according to a further feature of the invention, the molded part isfastened by two noses formed in the elastic intermediate layer.

In order to precisely fasten the elastic intermediate layer and this wayto facilitate the joining of the rail with the frame, the elasticintermediate layer is fastened to the frame by a projection reachingover the upper edge of the frame. In addition, this considerablyimproves electric insulation between the rail and the frame.

According to a further feature of the invention, in the case of aprestressed elastic intermediate layer, the distance between the uppersurface limiting the rail base and the oppositely positioned framesurface running approximately parallel thereto is at least 5 mm.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a cross sectional view of the left half of a rail enclosedwithin a frame, wherein the lateral surfaces limiting the rail below therail head have angularly adjoining portions, while the inner lateralsurfaces limiting the frame are rectilinear;

FIG. 2 is a cross sectional view of the right half of the railrepresented in FIG. 1, but with another configuration of the connectionpiece provided underneath the rail base;

FIG. 3 is a cross sectional view of the left half of a rail surroundedby a frame, wherein the limiting lateral surfaces below the rail headare rectilinear, while the inner lateral surfaces limiting the frame arebent;

FIG. 4 is a cross sectional view of the right half of the railrepresented in FIG. 3, but with another configuration of the connectionpiece provided underneath the rail frame;

FIG. 5 is a cross sectional view of the left half of an elasticintermediate layer;

FIG. 6 is a cross sectional view of the right half of a standard railenclosed in a frame; and

FIG. 7 is a cross sectional view of the right half of another standardrail surrounded by a frame.

SPECIFIC DESCRIPTION

In the embodiment shown in FIGS. 1 and 2, the rail 1 rests with itslaterally limiting surfaces 2.0 located below the rail head 3 againstthe inner lateral surfaces 5 limiting the frame 6, with the elasticintermediate layers 4 arranged therebetween. Inside each elasticintermediate layer 4, chambers 7 are provided, which have approximatelythe shape of a rectangle. This rectangle extends in the direction of thelateral surfaces 2 bounding the rail web. The width B of the rectangularchamber 7, which diminishes when the rail 1 is under load, is soselected that it becomes zero when the normal load indicated by arrow N(compare FIG. 4) is reached. The elastic intermediate layers 4 onopposite flanks are connected to each other by a connection piece 9surrounding the rail base 8. Underneath the rail base 8, a free space 11is provided. This free space 11 can be provided between the rail base 8and the connection piece 9, as shown in FIG. 1, or it can be provided asin FIG. 2, between the connection piece 9 and the bottom 10 of the frame6. The connection piece 9 can be provided with projections 13, extendingover the entire height of the free space 11.

The inner lateral surfaces 5 limiting the frame 6 are rectilinear andform with the vertical S an angle W6, while the lateral surfaces 2limiting the rail web are bent so that their upper area 2.0 form withthe vertical S an angle W1.O and their lower area 2.U forms with thevertical S an angle W1.U.

In the embodiment shown in FIGS. 3 and 4, the lateral surfaces 2limiting the rail web are rectilinear and form thereby with the verticalS only an angle W1, while the inner lateral surfaces 5 limiting theframe 6 are bent so that their upper area 5.0 forms with the vertical San angle W6.O and their lower area 5.U forms with the vertical S anangle W6.U.

In this case also a free space 11 is provided underneath the rail base8. The height H of the free space 11 corresponds to the spring excursionE of the rail 1 under normal load N (compare to FIG. 4), so that alsothe height H of the free space 11 becomes zero under normal load N.Laterally with respect to the rail base 8, on the side facing away fromthe rail base, the connection piece 9 is provided with recesses 12(compare to FIG. 3).

FIG. 5 shows the left half of an elastic intermediate layer 4 in anonstressed state. On its side facing away from the rail 1, the elasticintermediate layer 4 is provided with approximately rectangularprojections 14, which serve for prestressing the elastic intermediatelayer 4 after its insertion.

Further, the elastic intermediate layer 4 has in its upper area on bothsides approximately triangular projections 15, which prevent thepenetration of water between the rail and the frame.

In the embodiment shown in FIG. 6, on both sides of the web 16 of astandard rail 1A molded parts 17 are attached. The surface 2A of themolded part 17, which is facing away from the web 16 of rail 1A takesover the function of a lateral surface limiting the web of rail 1A. Themolded part 17 is held by a lower nose 18 provided on the elasticintermediate layer 4A and an upper nose 19 located at the end of aprojection 20 of the elastic intermediate layer 4A, which reaches overthe molded part 17. In turn, the elastic intermediate layer 4A is heldby a projection 21 reaching over the upper edge of the frame 6A. On itslimiting surface 2A facing away from the web 16 of the rail 1A, themolded part 17 is provided with projections 24 of an approximatelytriangular shape, which prevent a displacement of the molded parts 17with respect to the elastic intermediate layer 4A.

The embodiment shown in FIG. 7 also has a standard rail 1A. In thisembodiment, the elastic intermediate layer 4B extends until it reachesthe web of the standard rail 1A. As can be further seen from thisembodiment example, a free space A is provided between the upper surface8.0 limiting the rail base and the surface 6.U defining the frame 6, thelatter surface facing away from the rail base and running somewhatparallel thereto.

I claim:
 1. A rail assembly for a rail-vehicle track, comprising:a rail having:a rail head, a base, and a shank connecting said head with said base and having a pair of outwardly facing downwardly and inwardly tapering flank shank surfaces; a frame flanking said rail and having a pair of downwardly tapering members forming a pair of inwardly facing flank frame surfaces spaced from and juxtaposed with the outwardly facing flank shank surfaces of said rail, said frame forming a base spaced below said base of said rail; and elastic intermediate layers disposed between the juxtaposed surfaces of said rail and said frame and prestressed between them with a spring constant from 2 KN/mm to 8 KN/mm per meter of rail length, the flank shank surfaces having:upper downwardly and inwardly tapering rectilinear portions, and lower downwardly and inwardly tapering rectilinear portions, said lower and upper rectilinear downwardly tapering portions angularly adjoining each other and forming different angles with a vertical, at upper ends of said upper rectilinear portions, upwardly and outwardly turned head surfaces being connected to said upper rectilinear portions, delimiting said head and defining steps between said head and said shank, the frame surfaces being rectilinear and of a single angle with a vertical over a height thereof juxtaposed with the shank surfaces.
 2. The rail assembly defined in claim 1 wherein said spring constant is substantially 3.5 KN/mm per meter of rail length.
 3. The rail assembly defined in claim 1 wherein said upper portions of said shank surfaces form angles with the vertical between 5° to 10°, said lower portions of said shank surfaces form angles with the vertical between 15° and 30° and said flank frame surfaces form angles with the vertical between 5° and 30°.
 4. The rail assembly defined in claim 1 wherein each of said elastic intermediate layers is formed with a plurality of internal chambers.
 5. The rail assembly defined in claim 4 wherein said chambers are dimensioned so that said rail has a spring excursion between 1 millimeter and 15 millimeters wherein said rail receives a normal load from a vehicle thereon.
 6. The rail assembly defined in claim 5 wherein said chambers are dimensioned such that such excursion is substantially 6 millimeters when said rail receiver said normal lead.
 7. The rail assembly defined in claim 6 wherein said chambers are substantially of the cross sectional shape of rectangles elongated along said flank shank surfaces of said rail and of a width decreasing to zero when the rail is under said normal load.
 8. The rail assembly defined in claim 4 wherein two of said chambers is provided in each of said elastic intermediate layers.
 9. The rail assembly defined in claim 1 wherein said elastic intermediate layers are mutually connected by a connection piece extending below said base of said rail and having a resiliency corresponding to the resiliency of said elastic intermediate layers, a clearance being provided between said connection piece and said base of said rail of a height corresponding to a spring excursion of said rail when it reaches a normal load.
 10. The rail assembly defined in claim 9 wherein said connection piece is formed with spaced apart projections extending over said height.
 11. The rail assembly defined in claim 1 wherein said elastic intermediate layers are formed at upper regions thereof with projections of an approximately triangular cross sectional shape filling gaps between said head and said tapering members of said frame. 